After Effects Error Asked To Create Unknown Property Of Type Fix Jun 2026

If the application displays an endless error loop before you can even view your timeline, corrupt global preferences are likely blocking standard composition initialization.

Using older project files or templates with expressions built for older versions of the After Effects Javascript engine. Essential Graphics/Master Properties:

If the error involves expressions, Adobe provides a built-in tool: If the application displays an endless error loop

Let After Effects scan your timeline and automatically translate old syntax rules to the modern JavaScript engine.

The "After Effects error: asked to create unknown property of type" is a common but frustrating warning that typically indicates a mismatch between the software and the project's scripts, expressions, or plugins. This error often occurs when After Effects encounters a "pseudo-effect" or a custom property it doesn't recognize Common Causes Outdated Expressions The "After Effects error: asked to create unknown

This error is almost never caused by a bug in After Effects itself. It is almost always caused by:

If the project crashes immediately upon opening due to this error, use the : Launch Adobe After Effects with a fresh, empty composition. Launch After Effects and start a completely blank,

Launch After Effects and start a completely blank, new project. Go to > Import > File .

After Effects will treat the old project as a folder asset, frequently bypassing the structural script loops that trigger the startup crash. Save this as a new file. 2. Re-Naming and Fixing Custom Pseudo Effects